1. Field of the Invention
The present invention relates to transceivers used in Ethernet type cable based networks, and more specifically to a method and apparatus which enables auto-configuration of such transceivers to connect transmit and receive ports to corresponding ports on the other end irrespective of cable connection mis_match.
2. Related Art
Devices often contain transceivers (hereafter “transceivers”) which transmit and receive signals on different paths (hereafter cables). To facilitate such transmission and reception, each transceiver generally contains a receive pin and a transmit pin. Thus, the receive pin is connected to one cable (“receive cable” merely for explanation) and the transmit pin is connected to another cable (“transmit cable”).
Transceivers generally also contain a transmit port on which an internal circuit (transmit circuit) makes the signal available for transmission, and a receive port on which another internal circuit (receive circuit) receives a signal received from external sources.
In one prior approach, the transmit pin(s) and receive pin are respectively hardwired to the transmit port and the receive port, and a user is accordingly required to accurately (manually) connect the transmit cable to the transmit pin and the receive cable to the receive pin. A cable connection mis-match is said to occur when the receive pin is connected to the transmit cable, and the transmit pin is connected to the receive cable.
A cable connection mis-match may be undesirable for several reasons. For example, in the case of Ethernet twisted pair cables connecting two devices (e.g., two repeaters or network interface card with a repeater) according to the above-noted prior approach, the transmit pin of one device is to be connected to the receive pin of the device at the other end by a cable. A mis-match may render the two devices non-operational, at least until the connections are switched.
Accordingly, at least to reduce the complexity of deploying the devices, there has been a generally felt need to auto-configure transceivers such that transceivers would be operable irrespective of the connection of the cables to the pins. In other words, the internal implementation within a transceiver would be automatically (re)configured in case of a wrong connection, to automatically (without manually switching the cables) cause the devices to communicate.
In one prior auto-configuration approach, substantial portion of the transmit and receive circuits are replicated at each pin and only either transmit or receive circuit is used at a pin (at a given time instance) depending on the cable connected. One problem with such an approach is increased area requirements and possibly additional exposure to failure due to the increased number of components. At least for such reasons, the prior auto-configuration approach may not suitable in several environments.
What is therefore required is an improved method and apparatus which enables auto-configuration of such transceivers to connect transmit and receive ports to corresponding ports on the other end irrespective of cable connection mis_match.